SMITHSONIAN   INSTITUTION 


SOURCES  OF  NITROGEN  COMPOUNDS  IN 
THE  UNITED  STATES 


BY 

CHESTER  G.  GILBERT 
Smithsonian  Institution 


(PUBLICATION  2421) 


CITY  OF  WASHINGTON 

PUBLISHED  BY  THE  SMITHSONIAN  INSTITUTION 
JUNE  30,   1916 


SMITHSONIAN   INSTITUTION 


SOURCES  OF  NITROGEN  COMPOUNDS  IN 
THE  UNITED  STATES 


BY 

CHESTER  G.  GILBERT 
Smithsonian  Institution 


(PUBLICATION  2421) 


CITY  OF  WASHINGTON 

PUBLISHED  BY  THE  SMITHSONIAN  INSTITUTION 
JUNE  30,   1916 


•  AtTIMORB.    MD  ,   0.  S. 


SOURCES  OF  NITROGEN  COMPOUNDS  IN  THE 
UNITED  STATES 

BY  CHESTER  G.  GILBERT 

SMITHSONIAN   INSTITUTION 

Nitrogen  by  itself  under  normal  conditions  is  a  gas.  Chemically 
it  is  a  notoriously  sluggish  inert  element  in  its  gas^piis 'molecular 
state,  indisposed  toward  the  activity  of  entering  into  mineral- forming" 
combinations  with  other  elements.  In  the  general 'process  :pf  <?ja£$a 
evolution  its  more  energetic  elemental  competitors  have  effected  the 
various  mineral  combinations  and  progressive  readjustments  involved 
m  the  formation  of  the  outer  lithosphere,  relegating  the  passive  nitro- 
gen element  almost  exclusively  to  the  atmosphere.  Thus  it  happens 
to-day  that,  with  four-fifths  of  the  bulk  of  the  atmosphere  made  up 
of  nitrogen  gas,  the  relative  amount  entering  mineralogically  into  the 
make-up  of  the  earth's  immediate  exterior  as  a  whole  is  inappreciable. 
Thus,  too,  with  nitrogen  dominating  the  very  air  itself  in  all  its  inti- 
macy of  relationship  to  life,  the  world  has  nevertheless  been  brought 
to  face  a  vital  problem  in  the  scarcity  of  nitrogen  in  substantial  form. 

Passive  and  inconsequential  though  it  is  in  the  simple  form  of 
nitrogen,  combinations  with  other  chemical  elements,  once  formed, 
are  some  of  them  capable  of  the  greatest  chemical  energy  and  prac- 
tical utility.  Familiar  examples  are  the  particular  combination  of 
nitrogen  with  oxygen,  yielding  nitric  acid,  and  that  with  hydrogen, 
forming  ammonia  ;  and  it  is  the  bringing  about  of  such  combinations 
on  the  part  of  free  nitrogen  which  is  implied  in  the  technical  expres- 
sion nitrogen-fixation.  Another  important  form  of  nitrogen  com- 
pound, though  less  familiar  in  everyday  use,  is  the  deadly  poisonous 
one  with  carbon,  known  as  cyanogen.  In  addition  to  nitric  oxide,  the 
basis  of  nitric  acid,  nitrogen  and  oxygen  also  combine  in  three  other 
ratios,  and  there  are  an  almost  endless  number  of  other  chemical 
compounds  in  which  it  appears,  from  simple  ones  where  it  assumes 
the  basic  role,  such  as  nitrogen  sulphide,  to  highly  complex  ones, 
such  as  the  nitro-phenol  derivatives  especially  noteworthy  for  their 
explosive  properties.  The  latter,  however,  have  only  specialized  uses, 
and  are  mostly  prepared  by  the  employment  of  nitrogen  already  fixed 
in  one  or  another  of  the  first  named  forms,  so  these  three — that  of 


745915 


•  2  SMITHSONIAN    INSTITUTION 

nitrogen  with  oxygen  in  the  form  of  nitric  acid  and  the  nitrate  salts, 
that  with  hydrogen  in  the  form  of  ammonia  and  ammonia  salts,  and 
that  with  carbon  in  the  form  of  prussic  acid  and  the  cyanide  salts- 
constitute  the  fundamentally  significant  group  of  fixed  nitrogen  com- 
pounds. It  is  these  for  which  constant  search  has  been  conducted 
in  the  realms  of  both  organic  and  inorganic  nature  with  ever- 
increasing  pressure  of  requirement  throughout  the  history  of  modern 
civilization;  and  more  recently  it  is  the  inadequacy  of  the  returns 
from  natural  sources  which  has  led  the  search  further  afield  from 
tin-  rcaluis  Af.t.hejrcal  into  those  of  synthesis,  and  led  to  the  develop- 
'hkrit  oL  nJtrbg'eiiVfixation  processes. 

:  tCJ^eu»u?aJ  elements'  toiay  be  totally  insignificant  as  factors  in  earth 
stViii:HriH?Vand*Vet"%c"entribute  very  substantially  to  localized  occur- 
rences ;  in  fact,  this  is  commonly  the  case.  Nitrogen,  however,  has 
been  handicapped  with  the  serious  disadvantage  of  having  no 
stable  form  of  mineral  occurrence  which  is  not  readily  soluble  in 
water.  Obviously  then  an  arid  climate  is  essential  to  the  accumu- 
lation of  mtrate  mineral  deposits  on  any  great  scale.  Including  with 
this  special  requirement  the  natural  indisposition  of  the  element  itself 
toward  mineral-forming  activity,  the  combined  requirements  have 
proven  so  nearly  prohibitive  that  so  far  as  is  known  the  desert  areas 
of  Chile  and  Peru  alone  have  been  able  to  meet  them  to  the  extent 
of  providing  deposits  of  any  great  economic  importance. 

The  organisms  of  life  contain  nitrogen,  and  some  of  this  is  carried 
over  into  such  derivatives  as  peat  and  coal.  As  a  matter  of  fact, 
nitrogen  is  regularly  occurrent  in  association  with  carbon,  not  only 
in  the  coal  series  but  also  in  that  of  the  hydrocarbons.  As  much  as 
10  per  cent  of  nitrogen  has  been  reported  in  this  association,  but  the 
percentage  lies  rather  uniformly  between  I  and  2.  Such  amounts 
are.  of  course,  in  themselves  negligible,  and  this  form  of  nitrogen 
occurrence  only  began  to  assume  importance  with  the  modern  devel- 
opment of  industrial  chemistry's  capabilities  along  the  lines  of  by- 
product recovery.  In  a  by-product  capacity  the  nitrogen  content  has 
already  come  to  be  a  significant  factor  in  connection  with  a  wide 
range  of  chemical  industries  operating  on  the  products  of  organic 
life,  both  of  the  present  day  and  of  the  geologic  past.  Thus  far  the 
list  of  by-product  fixed  nitrogen  sources  in  this  category  includes 
by-product  coking,  with  its  more  or  less  closely  related  illuminating 
gas.  producer  gas.  and  blast  furnace  associations,  peat  treatment,  oil 
shale  distillation,  sewage  disposal,  garbage  rendering,  wine  manu- 
facture, and  bone  carbonizing.  Of  this  list,  the  coal  product  group 
nets  the  only  really  important  yield  at  present.  Along  the  other  lines 


NITROGEN    COMPOUNDS GILBERT  3 

either  the  supporting  industries  themselves  are  as  yet  undeveloped, 
as  in  the  case  of  oil  shale  operations,  or,  as  in  the  case  of  blast  furnace 
operations,  the  opposite  may  be  true,  in  the  form  of  a  development 
too  mature  to  afford  the  flexibility  of  adaptation  to  by-product  modi- 
fications. It  is  safe  to  say,  however,  that  the  range  of  possibilities 
for  nitrogen  recovery  in  this  general  direction  has  by  no  means  been 
exhausted,  and  that  other  instances  will  be  added  to  the  coal  product 
one,  wherein  combined  nitrogen  will  appear  prominently  in  contrib- 
uting to  the  profit-forming  margin  by  which  new  or  reorganized 
lines  of  chemical  industry  are  supported. 

With  the  extension  of  chemical  needs  such  as  are  offered  by  the 
development  of  cyaniding  in  metallurgy,  and  of  refrigeration  in  the 
preservation  of  foodstuffs,  and  more  especially  with  the  extension  of 
the  need  for  artificially  provided  fertilizers,  nitrogen  compounds  have 
,come  to  be  necessary  not  only  to  the  welfare,  but  to  the  very  existence, 
of  a  people  living  under  modern  conditions  of  economic  development. 
At  the  outset  the  Chilean  mineral  nitrate  deposits  bore  the  brunt  of 
the  responsibility  in  providing  for  these  growing  needs.;  but  more 
recently  the  gradual  development  of  the  by-product  feature  in  chemi- 
cal industries,  more  especially  in  the  field  of  coal  products,  has  intro- 
duced a  very  material  competitor  with  the  natural  sources,  matching 
their  two  and  a  half  million  tons  of  annual  output  in  nitrate  of  soda 
with  around  two  million  tons  of  sulphate  of  ammonia.  Even  the 
combined  sources  have,  however,  proven  insufficient  to  maintain 
reserves  with  which  to  meet  the  world's  ever-increasing  demands. 
In  1898  Sir  William  Crookes  called  attention  to  this  inadequacy  and 
pointed  to  atmospheric  nitrogen  fixation  as  the  only  preventive  rem- 
edy for  an  -impending  economic  breakdown.  Recent  events  have 
emphasized  the  truth  of  this  prediction,  and  brought  the  United  States 
to  a  consideration  of  its  national  responsibilities  in  this  direction. 

Various  means  have  been  evolved  in  the  chemical  laboratory  for 
effecting  the  fixation  of  atmospheric  nitrogen  through  enforced 
combination,  such  as  that  with  atmospheric  oxygen  or  with  hydrogen, 
both  of  which  resultant  combinations  are  absorbable  in  water  to  form 
nitric  acid  and  ammonia  water,  respectively.  Nitrogen,  however, 
owing  to  the  extreme  inertness  of  its  gas  molecule,  is  difficult  to 
stimulate  into  combination,  and  as  a  result  most  of  the  processes 
evolved  have  been  found  to  offer  such  little  encouragement  toward 
efficient  commercial  practicability  that  to  include  all  of  them  in  any 
purely  industrial  discussion  would  serve  only  to  introduce  so  many 
profitless  elements  of  complexity.  Accordingly,  while  any  one  of 


4  SMITHSONIAN    INSTITUTION 

the  several  other  processes  of  more  or  less  claim  to  merit  may  in 
some  future  time  force  its  way  to  the  front  over  what  seem  now  to 
be  insurmountable  obstacles,  there  are  to-day  only  three  methods 
which  have  stood  up  under  commercial  test  sufficiently  to  warrant 
definite  consideration  in  a  summary  discussion.  The  three  are  known 
as  the  arc  method,  the  Cyanamide  process,  and  the  Haber  process  of 
nitrogen  fixation.  Adding  then  the  coal  products  source  of  fixed 
nitrogen,  there  are  four  currently  prominent  commercial  sources  of 
fixed  nitrogen  available  for  development  to  meet  varying  needs 
within  the  country. 

I.  ARC  METHOD 

If  a  current  of  air  be  passed  through  an  electric  arc  some  of  the 
oxygen  and  nitrogen  of  which  the  atmosphere  is  composed  enter  into 
chemical  combination  as  oxides  of  nitrogen,  which  may  then  be 
treated  chemically  for  complete  oxidation  and  absorbed  in  water  to 
form  nitric  acid.  Thus  a  limitless  source  of  the  requisite  ingredients 
is  provided  right  on  the  spot  without  the  least  cost  whatever;  the 
chemistry  involved  is  apparently  of  the  very  simplest,  most  direct 
order,  and,  moreover,  the  method  is  in  actual  operation  on  a  commer- 
cial scale.  Superficially,  therefore,  the  project  would  seem  to  be  just 
about  ideal,  and  presents  one  of  the  most  alluring  prospects  offered  in 
the  field  of  chemical  technology.  The  underlying  difficulties  in  this 
problem  are  to  be  found  in  the  inherent  fact  that  nitrogen  is  chemi- 
cally inert  and  extremely  difficult  to  stimulate  into  the  activity  of 
entering  into  combination.  This  fact  is  forced  home  by  the  reflection 
that  throughout  the  ages  of  the  earth's  existence  its  atmosphere  has 
consisted  of  the  self-same  oxygen  and  nitrogen  most  intimately 
mixed,  and  had  there  been  the  least  susceptibility  on  the  part  of  the 
nitrogen,  its  complete  combination  with  the  oxygen  would  long  ages 
ago  have  been  effected,  and  instead  of  our  now  being  engaged  in 
trying  to  make  them  combine,  there  would  be  an  atmosphere  devoid 
of  life-sustaining  oxygen,  and  in  place  of  water  our  oceans  would  be 
of  concentrated  acid.  That  same  property  of  chemical  inertness  on 
the  part  of  nitrogen  which  is  the  salvation  of  life  itself  on  the  earth 
has  proven  well-nigh  disastrous  to  the  commercial  practicability  of 
the  arc  method  of  nitrogen  fixation,  owing  to  the  enormous  electric 
power  consumption  involved. 

In  its  present  state  of  efficiency  the  arc  method  operations  require 
roughly  2.75  to  3.00  H.  P.  year  of  electric  power  per  ton  of  nitric 


NITROGEN    COMPOUNDS GILBERT  5 

acid  yield.1  Now  the  average  private  cost  of  power-site  develop- 
ment in  this  country  has  been  over  $120  per  horsepower.  Counting 
an  operative  interest  rate  of  8  per  cent  to  finance  the  development 
proposition,  and  then  including  the  other  necessary  items  of  deprecia- 
tion, overhead  charge,  etc.,  a  total  of  12  per  cent  or  13  per  cent  on 
each  horsepower  of  development,  or  about  $15  per  horsepower  year, 
is  a  fair  estimate  of  costs  under  present-day  conditions  in  this  country. 
Then  the  2.75  H.  P.  requisite  for  the  fixation  of  the  nitrogen  in  one 
ton  of  nitric  acid  means  a  cost,  roughly,  of  over  $40  per  ton  of  product 
in  power  expense  alone. 

The  item  of  $40  per  ton  of  nitric  acid,  it  must  be  remembered,  takes 
into  consideration  power  costs  alone,  and,  moreover,  represents  a 
product  for  which  under  ordinary  conditions  there  is  no  great  market, 
so  it  would  have  to  be  converted  to  calcium  nitrate  for  use  as  fertilizer. 
But  calcium  nitrate  absorbs  moisture  with  avidity,  and  has  not  proven 
itself  adaptable  to  American  fertilizer  requirements  where  the  cost 
of  labor  renders  mechanical  sowing  desirable;  and,  moreover,  its 
fertilizer  equivalent  in  Chile  nitrate  of  soda  is  already  available  at 
around  $40  per  ton,  so  the  arc  method  cannot  be  made  to  stand  on 
its  own  feet  in  this  country  under  present  conditions  to  the  extent 
of  contributing  significantly  toward  the  country's  material  well-being. 
Owing  to  the  opportunity  for  securing  lower  interest  rates,  it  would 
be  possible  for  the  Government  to  develop  power  at  a  much  lower 
cost,  commonly  estimated  at  $8  per  horsepower  year.  This  would 
cut  the  power  costs  to  around  $22  per  ton  of  nitric  acid,  but  even  then 
the  enormous  power  requisites  and  the  inadaptability  of  the  product 
remain  as  unsurmounted  obstacles. 

The  Government  has  under  consideration  at  this  writing  a 
$20,000,000  project  for  atmospheric  nitrogen  fixation  primarily  as  a 
military  measure,  and  it  may  be  of  interest  in  passing  to  interpret 
the  efficiency  of  such  a  project  in  terms  of  the  hydroelectric  arc 
method.  If  the  entire  sum  were  to  be  put  into  power-site  develop- 
ment, it  would  furnish  somewhere  around  150,000  H.  P.,  capable  of 


1The  atmospheric  nitrogen  fixation  industry  is  still  in  its  first  stages  of 
evolution,  and  the  figures  available  for  the  various  processes  are  only  such 
as  are  divulged  from  sources  still  actually  involved.  Moreover,  the  whole 
proposition  is  one  offering  no  criteria  for  estimates  other  than  those  derived 
from  actual  operations.  Accordingly,  no  credit  for  originality  belongs  with 
the  publication  of  this  paper,  and  on  the  other  hand  the  only  responsibility  is 
for  an  honest  attempt  at  interpretation.  Every  care  has  been  exercised  in 
checking  up  figures  before  their  employment  and  there  is  every  reason,  short 
of  actual  operative  proof,  for  their  acceptance. 


6  SMITHSONIAN    INSTITUTION 

yielding  in  the  neighborhood  of  50,000  tons  of  nitric  acid,  or  about 
one-fourth  the  estimated  military  emergency  requirement  alone ;  and 
at  that,  the  entire  cost  of  the  plant  installation  and  operation,  running 
into  the  millions  of  dollars,  would  have  to  be  additional.  To  satisfy 
Government  estimates  of  around  200,000  ton  war-time  requirements 
would  entail  a  power  generation  of  around  600,000  H.  P.,  or  some 
50,000  H.  P.  more  than  the  total  Niagara  power  development.  Such 
a  project  would  cost  around  $80,000,000  to  eventuate,  and  in  its 
operation  during  peace  times  as  an  agricultural  proposition  in  com- 
petition with  other  sources  would  necessitate  an  annual  subsidy  run- 
ning into  the  millions  of  dollars,  without  offering  a  single  advantage 
excepting  as  a  preparedness  measure.  Norway,  with  three  or  four 
dollar  power,  has  been  able  to  develop  the  arc  method  on  a  self- 
supporting  basis,  but  with  a  power  consumption  of  around  3  H.  P. 
per  ton  the  difference  between  $3  and  $15,  or  even  the  possible  $8 
of  Government  cost,  is  precisely  that  between  success  and  failure.1 

II.  CYANAMIDE  PROCESS 

The  so-called  Cyanamide  process  of  nitrogen  fixation  is  dependent 
upon  the  fact  that  calcium  carbide  may  be  induced  with  comparative 
ease  to  absorb  nitrogen,  thus  forming  a  combination  of  calcium, 
carbon  and  nitrogen,  known  commercially  as  cyanamide.  Thus,  un- 
like the  direct  arc  product,  cyanamide  involves  raw  materials  in  the 
form  of  limestone  and  coal,  or,  rather,  their  derivatives,  lime  and 
coke.  The  lime  and  coke  are  fused  together  to  form  carbide,  which 
is  then  inserted  in  finely  ground  condition  in  an  electric  furnace  where 
a  temperature  of  1,000°  C.  is  maintained,  while  a  stream  of  nitrogen 
gas  already  separated  out  from  the  oxygen  of  the  air  is  fed  in  and 
absorbed  by  the  powdered  carbide.  The  product  is  a  mixture  of 
cyanamide,  excess  carbide,  and  lime,  which,  after  being  hydrated  to 
get  rid  of  the  free  carbide  and  caustic  lime,  is  ready  for  the  market 
as  nitrogen-bearing  fertilizer.  By  treating  this  cyanamide  with 
superheated  steam  its  nitrogen  may  be  released  to  enter  into  com- 
bination with  the  hydrogen  of  the  steam,  forming  ammonia,  which, 
if  4esirable,  may  in  turn  be  burned  with  air  to  form  nitric  acid. 


1  It  is  to  be  borne  in  mind  throughout  this  paper  that  any  and  all  estimates 
and  deductions  refer  purely  to  developments  of -nationally  significant  scale, 
and  have  not  the  least  bearing  upon  the  feasibility  of  localized  private  enter- 
prises with  the  special  opportunities  which  may  be  afforded.  The  one  attempt 
to  apply  an  arc  process  in  this  country,  the  purely  experimental  one  at 
Nitrolee,  South  Carolina,  may,  however,  be  quoted  in  substantiation. 


NITROGEN    COMPOUNDS GILBERT  7 

Thus  the  Cyanamide  process  affords  three  main  products  in  direct 
sequence  from  the  raw  ingredients  employed,  namely,  cyanamide, 
ammonia,  and  nitric  acid,  with  nitric  acid  the  end  point  instead  of  the 
first  product  to  be  derived,  as  is  the  case  with  the  employment  of  the 
arc  method.  Carrying  the  process  clear  through  to  the  nitric  acid 
stage,  the  power  consumption  is  approximately  J  H.  P.  year  per  ton 
of  nitric  acid,  or  about  one-sixth  to  one-fifth  that  requisite  for  the 
arc  method ;  the  raw  materials  employed  are  roughly  a  half  ton  each 
of  lime  and  coke ;  the  labor  items  involved  in  the  two  processes  are 
to  all  practical  purposes  equal ;  and  the  normal  peace  time  first 
product  from  the  Cyanamide  process,  calcium  cyanamide,  has  proven 
thoroughly  applicable  to  agricultural  use.  Comparison  of  the  two 
processes  with  reference  to  their  relative  values  toward  meeting  the 
country's  needs  offer,  first  of  all,  a  saving  of  four-fifths  to  five-sixths 
the  power  consumption  in  favor  of  the  Cyanamide  process.  To 
appreciate  the  significance  of  this  item  it  is  only  necessary  to  reflect 
that,  whereas  the  country's  estimated  200,000  tons  requirement  calls 
for  a  power  supply  of  over  a  half  million  horsepower  year  in  the  one 
case  as  against  one  of  only  100,000  H.  P.  year  in  the  other,  the 
difference  is  not  merely  one  of  economics,  but  of  availabilities  as  well. 
Again,  the  normal  product  from  the  arc  method  is  one  whose  chief 
demand  is  founded  upon  abnormal  war  times,  while  the  normal  first 
product  from  the  other  is  an  agricultural  one,  fitting  into  normal 
conditions.  Again,  the  regular  product  from  the  arc  method  is  not 
convertible  to  meet  peace-time  requirements  adequately,  while  the 
product  from  the  other  is  readily  convertible  to  the  emergency  nitric 
acid  form.  Standing  alone  in  prominent  opposition  is  the  fact  that 
raw  ingredients  enter  into  the  manufacture  of  the  cyanamide 
product;  but  even  this  one  opposing  element  will  hardly  loom  so 
conspicuously  when  the  carbon  electrode  consumption  involved  indi- 
rectly in  arc  method  procedure  is  considered.  Ignoring  indirect 
elements,  however,  the  raw  materials  employed  entering  into  cyana- 
mides  involve  a  resource  expenditure  about  the  equivalent  of  a  fifth 
that  of  arc  method  power  under  average  American  conditions.  The 
difference  between  the  two  in  significance  amounts  to  that  of  three- 
fifths  to  two-thirds  of  the  total  power  involved  in  arc  method  manu- 
facture, plus  the  value  of  a  product  normally  in  demand  as  against 
that  of  one  for  which  there  is  very  little  normal  demand.1 


1  Since  power  cost  is  the  dominant  item  of  expense  m  the  arc  method  while 
it  represents  only  about  a  third  of  the  fundamental  expense  connected  with 
the  cyanamide  method,  it  is  obvious  that  as  power  costs  are  reduced  the  purely 


8  SMITHSONIAN    INSTITUTION 

III.  HABER  PROCESS 

Bearing  in  mind  that  ammonia  is  a  chemical  combination  of  nitro- 
gen and  hydrogen  in  the  ratio  of  one  atom  of  the  former  to  three 
of  the  latter,  synthetic  ammonia  would  result  if  a  properly  propor- 
tioned mixture  of  the  two  gases  in  purified  condition  can  be  prevailed 
upon  to  react  chemically.  With  the  two  essential  ingredients  readily 
available,  the  one  from  air,  the  other  from  water,  the  only  problem  is 
that  of  inducing  chemical  reaction.  By  what  is  known  as  the  Haber 
process  a  means  of  effecting  the  necessary  stimulus  has  been  pro- 
vided, and  the  Haber  process  of  fixation  is  on  a  commercial  basis  in 
Germany,  where,  from  the  last  available  figures,  it  was  netting  at  the 
rate  of  about  200,000  tons  of  ammonium  sulphate  per  year.  The 
agency  for  combination  employed  in  the  Haber  process  is  compres- 
sion of  the  mixed  gases  in  the  presence  of  a  catalyzing  agent.  This 
results  in  a  partial  combination  of  the  two  gases  to  form  ammonia, 
which  may  be  absorbed  out  and  the  uncombined  portion  of  the  origi- 
nal gaseous  charge  returned  for  renewed  treatment.  The  process 
does  not  make  the  high  demands  on  electrical  power  required  by  the 
other  processes  of  atmospheric  nitrogen  fixation  in  use,  but  involves 
technical  difficulties  in  the  way  of  manipulation  which  have  prevented 
the  proportionate  extension  of  its  use,  even  in  Germany  under  pres- 
ent exigencies.  No  opportunity  for  an  analysis  of  comparative  costs 
is  available,  but  the  fact  that  the  use  of  the  process  has  not  been 
extended  proportionately  even  in  Germany,  where  cheap  skilled  labor 
and  military  exigency  have  combined  to  give  it  every  advantage  over 
conditions  in  this  country,  may  well  be  taken  as  evidence  that  the 
process  has  not  yet  been  perfected  to  a  point  where  it  is  able  to  qualify 
for  final  consideration. 

IV.  BY-PRODUCT  AMMONIA 

Mention  has  already  been  made  of  combined  nitrogen  as  a  by- 
product from  chemical  industries  based  upon  the  products  of  organic 
life  both  of  the  present  day  and  of  the  geologic  past;  and  coal- 
product  operations  were  cited  as  the  most  advanced  forerunner  in 
this  direction.  With  the  wastefulness  of  method  characteristic  of 


financial  aspects  of  the  two  methods  converge.  These  converging  lines  cross 
at  the  point  indicated  by  $5.00  power.  It  would  seem,  however,  out  of  the 
question  that  under  present-day  conditions  power  on  sufficiently  huge  scale 
to  carry  a  significant  arc  process  plant  is  capable  of  development  in  this 
country,  and,  accordingly,  the  fact  of  convergence  toward  a  $5.00  H.  P. 
year  point,  while  interesting,  can  hardly  enter  as  a  determining  factor. 


NITROGEN    COMPOUNDS GILBERT  9 

American  industrial  practice,  by-product  development,  even  with 
reference  to  coal,  has  been  unreasonably  slow,  and  out  of  a  possible 
700,000  tons  the  actual  combined  nitrogen  recovery  in  the  form  of 
ammonium  sulphate  is  only  about  225,000  tons.  Of  late,  however, 
the  rate  of  increase  has  been  stimulated  to  such  an  extent  that  with 
the  completion  of  the  by-product  ovens  now  building  the  annual 
capacity  for  output  will  be  around  400,000  tons,  and  it  is  fair  to 
assume  that  if  the  tendency  is  unchecked  by  external  influences  the 
full  coking  yield  of  ammonia  will  be  available  to  the  country's  use 
within  the  next  f«w  years. 

The  actual  development  of  combined  nitrogen  returns  from  other 
by-product  directions  has  been  negligible,  and  they  assume  signifi- 
cance only  in  their  possible  bearing  upon  the  future  establishment 
and  growth  of  industries  important  to  the  country's  welfare.  From 
this  viewpoint  their  potential  significance  is  scarcely  less  real  than  it 
is  with  reference  to  by-product  coking.  This  country  is  bound  to  be 
the  greatest  coke  manufacturing  one  in  the  world,  and  the  desirability 
of  developing  the  enormous  by-product  possibilities  thus  opened  up, 
entirely  apart  even  from  the  half  million  to  million  tons  of  ammonium 
sulphate  now  directly  under  consideration,  is  scarcely  to  be  over- 
estimated. The  country  cannot  afford  to  take  any  step  which  will 
further  hinder  progress  along  these  general  lines. 

The  normal  first  product  from  the  arc  method  of  atmospheric  nitro- 
gen fixation  is  nitric  acid ;  that  from  the  Cyanamide  process  is 
calcium  cyanamide;  that  from  the  Haber  process  is  sulphate  of 
ammonia ;  and  that  of  by-product  derivation  is  also  ammonia,  either 
in  the  form  of  ammonia  liquor  or  ammonium  sulphate.  For  muni- 
tions use  the  acid  form  is  required,  while  agricultural  and  other  more 
usual  requirements  employ  either  ammonium  sulphate  or  some  other 
neutralized  form  of  combined  nitrogen.  The  original  character  of 
first  product  is  not  necessarily  of  any  great  moment,  however,  in 
view  of  the  fact  that,  once  fixed,  the  form  of  combination  is  suscep- 
tible of  change.  Thus,  the  original  nitric  acid  of  the  arc  method 
may  be  neutralized  to  a  nitrate  salt,  usually  that  of  calcium  because 
of  the  cheapness  of  the  calcium  source  in  limestone ;  cyanamide  may 
be  forced  to  yield  up  its  nitrogen  in  the  form  of  ammonia,  which  in 
turn  may  be  oxidized  to  nitric  acid ;  and  the  same  is  true  of  the  Haber 
process  sulphate.  By-product  ammonia,  however,  offers  at  present 
an  obstacle  to  such  flexibility  of  application,  in  the  form  of  impurities 
which  stand  in  the  way  of  effecting  the  delicately  balanced  reactions 
involved  in  the  oxidation  of  ammonia  to  nitric  acid. 


10  SMITHSONIAN    INSTITUTION 

In  view  of  the  feasibility  of  effecting  chemical  readjustments,  the 
problem  before  the  country  is  not  one  purely  or  even  primarily  of 
military  exigency,  but  rather  of  agricultural  betterment  with  military 
reservations.  The  country  is  capable  of  absorbing  an  indefinitely 
greater  amount  of  nitrogen  compounds  agriculturally,  and  of  doing 
so  to  ever-increasing  advantage  to  all  concerned,  provided  only  there 
is  no  sudden  glutting  of  the  market  demand  for  it  and  that  the  cost 
is  maintained  sufficiently  low  to  put  a  premium  on  intensive  land 
cultivation.  The  real  problem,  then,  is  that  of  developing  sources  of 
combined  nitrogen  such  that  their  costs  will  not,  as  they  do  to-day, 
counterbalance  the  farmer's  returns,  making  intensive  effort  profit- 
less, and  at  the  same  time  of  avoiding  any  such  precipitancy  of  action 
with  reference  to  new  sources  as  will  tend  to  demoralize  the  market. 
If  it  fails  to  do  the  former,  now  that  the  matter  has  come  up  definitely 
for  action,  it  will  be  failing  to  meet  national  responsibility  of  the 
greatest  importance ;  if  it  fails  to  do  the  latter,  consequences  as  dis- 
astrous to  the  country's  welfare  as  any  nitrogen  shortage  will  result 
in  the  further  hindrance  of  by-product  development. 

The  nitrogen  situation  is  one  involving  the  whole  structure  of  the 
country's  economic  development.  Off  hand,  exception  may  be  taken 
to  this  assertion  on  the  grounds  that  the  fundamental  issue  is  one  of 
military  importance  and  may  well  be  kept  within  those  confines.  Let 
any  one  who  is  disposed  toward  such  an  opinion  evolve  a  solution 
whose  efficacy  is  based  purely  upon  a  military  need;  then  let  him 
proceed  to  work  out  a  balance  sheet  covering  the  operation  of  the 
resultant  project  over  a  period  even  of  only  five  years.  The  scope 
of  the  issue  broadens  to  include  an  agricultural  aspect.  Since  nitro- 
gen compounds  may  be  prepared  which  are  convertible  between 
agricultural  and  military  needs,  and  since  an  adequate  nitrogenous 
fertilizer  supply  constitutes  an  invaluable  economic  asset,  it  may 
appear  next  that  the  situation  resolves  itself  fixedly  into  the  mere 
problem  of  determining  the  means  calculated  to  provide  the  largest 
output  of  convertible  nitrogenous  compounds  at  the  least  cost.  But 
industries  no  less  important  than  a  nitrogen-fixation  one  to  the  coun- 
try's economic  balance  are  involved  in  this  field,  and  any  governmental 
action  in  the  nitrogen  situation  which  would  be  disastrous  in  its  effect 
on  private  initiative  in  the  related  industries  would  be  inadvisable. 
Thus  the  scope  of  the  issue  widens  not  only  beyond  the  strict  con- 
fines of  military  need,  but  beyond  those  of  agriculture  as  well,  and 
action,  to  be  of  well-founded,  permanently  constructive  value,  must 
take  cognizance  of  the  whole  situation. 


NITROGEN    COMPOUNDS GILBERT  II 

SUMMARY 

To  summarize  a  situation  of  such  magnitude  adequately  in  a  few 
pages  is  not  only  difficult,  but  becomes  increasingly  so  the  more  it 
unfolds  with  study.  Accordingly,  in  the  foregoing  pages  the  aim 
has  been  rather  to  point  out  in  a  general  way  the  nature  of  the 
problem  confronting  the  country  than  to  attempt  any  analysis  of  its 
various  factors,  much  less  to  offer  any  complete  solution.  In  sub- 
stance, the  following  expressions  with  reference  to  conditions  and 
the  inferences  seemingly  afforded  are  offered : 

Nitrogenous  compounds  are  essential  not  only  to  self-defense  but 
to  the  country's  capacity  for  self-support,  and  to  be  effective  the 
source  must  be  such  that  the  product  may  be  adaptable  to  meet  either 
requirement. 

The  arc  method  has  not  thus  far  demonstrated  capacity  to  meet  the 
agricultural  requirement  at  all,  or  even  the  defense  requirement 
efficiently. 

Definite  knowledge  concerning  the  Haber  process  is  lacking,  but 
its  record  of  achievement  is  against  it,  and  it  would  seem,  moreover, 
unsuited  to  American  conditions,  at  least  in  the  present  state  of  its 
development. 

The  Cyanamide  process  is  capable  of  a  development  which  will 
meet  the  requirements  for  a  cheapened  nitrogenous  fertilizer  source 
whose  form  of  nitrogen  content  is  readily  convertible  to  nitric  acid. 
The  process  is  already  a  prominent  factor  in  the  economic  well-being 
of  most  countries  of  older  civilization,  and  is  capable  of  similar  exten- 
sion in  the  United  States. 

By-product  coking  operations  afford  a  source  of  nitrogenous  com- 
pounds netting  the  country  an  annual  production  at  the  rate  of  over 
200,000  tons  of  ammonium  sulphate  now,  and  due  to  raise  this  total 
to  about  400,000  tons  with  the  completion  of  the  ovens  now  building. 
A  total  of  about  700,000  tons  would  be  possible  if  all  coking  were  of 
by-product  nature,  and  this  total  should  be  attained  within  the  next 
few  years.  No  practicable  means  for  its  oxidation  to  nitric  acid 
have  yet  been  found  in  this  country. 

By-product  ammonia  constitutes  the  country's  one  actual  asset  in 
the  form  of  nitrogenous  compounds.  It  has  a  rapidly  growing  yield 
of  very  great  importance  in  itself ,  but  of  even  greater  importance  as 
a  factor  contributing  largely  to  the  commercial  possibilities  of  a 
number  of  industrial  lines,  especially  that  of  coal  products.  The 
country  cannot  afford  to  run  any  risk  of  checking  development  along 
these  lines. 


12  SMITHSONIAN    INSTITUTION 

The  evolution  of  a  practicable  process  for  the  oxidation  of  by- 
product ammonia  to  render  present  resources  available,  with  the 
development  of  an  atmospheric  nitrogen  fixation  output  by  the  Cyan- 
amide  process  carefully  timed  to  meet  growing  demands  following 
a  reduction  in  the  retail  price  of  nitrogenous  fertilizer,  would  appear 
to  be  the  desirable  governmental  procedure  as  being  the  one  least 
liable  to  disastrous  consequences. 


THIS 


DATS 


AN  INITIAL  FINE  OF  25  CENTS 


W.mC.       TO  50  CENT.  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENS 
OVERDUE. 


Photomount 

Pamphlet 

Binder 

Gaylord  Bros.  Inc. 

Makers 
Stockton,  Calif. 

PAT.  JAN.  21.  1908 


YD  03960 


745915 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


